Re: [Qemu-devel] [PATCH] virtio: abort on fatal error instead of just exiting

[Markus Armbruster]

Igor Mammedov <address@hidden> writes:

> On Wed, 29 Jun 2016 14:49:59 +0200
> Markus Armbruster <address@hidden> wrote:
>
>> Igor Mammedov <address@hidden> writes:
>> 
>> > replace mainly useless exit(1) on fatal error path with
>> > abort(), so that it would be possible to generate core
>> > dump, that could be used to analyse cause of problem.
>> >
>> > Signed-off-by: Igor Mammedov <address@hidden>
>> > ---
>> >  hw/virtio/virtio.c | 24 ++++++++++++------------
>> >  1 file changed, 12 insertions(+), 12 deletions(-)
>> >
>> > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>> > index 7ed06ea..9d3ac72 100644
>> > --- a/hw/virtio/virtio.c
>> > +++ b/hw/virtio/virtio.c
>> > @@ -315,7 +315,7 @@ static int virtqueue_num_heads(VirtQueue *vq,
>> > unsigned int idx) if (num_heads > vq->vring.num) {
>> >          error_report("Guest moved used index from %u to %u",
>> >                       idx, vq->shadow_avail_idx);
>> > -        exit(1);
>> > +        abort();
>> 
>> What's wrong with a simple assert(num_heads <= vq->vring.num)?
> Nothing, it should work to as we don't use NDEBUG.
> My intent was to make core dump at the point and no to remove
> error message
> (though message's mostly useless for me as virtio is unfamiliar to me
> and  I had to dig into core dump to analyze issue).

Understand.

The solution we really want is of course putting the device in an error
state, where it stays until reset.